Looking at a random power brick I saw what looked like a range of voltages, which re-ignited my old idea of a lab power supply powered by a standard USB. But now with the PPS function of the USB standard you can directly ask for the exact voltage you want.

It needs to be gridfinity compatible to fit in a standard around which test platters can be built.

I choose to use the STM32G0 as it was at the time the cheapest ST MCU that supported USB PD.

I realized that most power bricks do not apply any feedback to the voltage. Meaning that if you increase the load then the voltage will drop. That is why I had to implement a PID control in my system to compensate for effects coming from a variable load.

For once I wanted a project that looked good and premium, that is why the design is very art déco.

This version is supporting only the normal range of the PPS standard: 3.3V -> 21V

The current max is 5A.

I recently discovered that there is an extended range of voltages going up to 48V. This version of the project cannot support that unfortunately. Although when I think of it, I rarely needed more than 21V on a bench power supply.

Technical challenge: I wanted to use a nice font on the device in particular with ligatures. Thanks to "mcufont" I was able to load the font for the normal range of characters but also the ligature range of characters. Then from the C code I was able to directly target the utf8 code of the ligature that I wanted to print. I want to clean up what I implemented and then pull request that into "mcufont" to properly manage ligatures from fonts in embedded systems.